This invention relates to collectors and particularly to collectors adapted to receive and discharge the exhaust gases of a gas turbine type power plant or other gas generating systems.
As is generally known in the art, collectors serve to receive exhaust gases from a gas generator so as to divert the exhaust gas streams. For example, a free turbine industrial power plant operation which has a shaft extracting power from the free turbine would include a collector axially downstream of the free turbine so as to divert the exhaust gases 90.degree. from the engine axis and away from the free turbine drive shaft.
Also, well known in the art, collectors are typically toroidally shaped and surround the power plant exhaust pipe, which in a free turbine installation as noted above would be downstream of the free turbine. Generally the collector has a radial or substantially radial inlet and a single discharge pipe. The flow entering the collector on the opposite side of the discharge pipe has to make a turn to reach the discharge pipe. As a consequence this turning flow produces a high pressure region at the opposite end of the discharge outlet.
This high pressure region in turn intereferes with the flow around the circumference of the inlet causing distortion of the inlet flow and generally impairing the capacity of the collector from discharging flow effectively. One of the solutions to such problems is to design a large collector that could accommodate a larger flow. Obviously, the solution not only adds to the size, weight and expense, it may not be tolerable where the envelope to accommodate the collector is not sufficiently large.
I have found that I can obviate the problems noted above by incorporating parallel spaced baffles extending from the inlet in the collector mounted in the plane of the collector and achieve the following:
1. obtain higher specific flows in a collector without introducing circumferential distortion of the inlet flow PA1 2. do not sacrifice structural integrity and PA1 3. reduce the size of an installation for a given collector capacity.
This invention also contemplates incorporating a screen or perforated plate to serve as a blockage located in proximity to the inlet opposite the discharge outlet and extending circumferentially to span the opening of the outlet. The porosity of the blockage is selected so that the pressure drop thereacross should approximate the velocity head of the flow egressing from between the baffle into the curved passage formed by the baffles and walls of the torus. The blockage should be used only in cases when even a small circumferential inlet distortion cannot be tolerated.